Method of manufacturing mold powder



Patented Apr. 2.7, 1926.

UNITED STATES PATENT OFFICE.

xomum nttnmmjor LUNEBUmaeEmrANY, assrenon 'ro 'rnr. FIRM B. noes a G0.or BERLIN, GERMANY.

METHOD OI MANUFACTURING MOLD POWDER.

Drawing To all whom it may concern:

Be it known that I, KONRAD Mr'iLLnn, a citizen of the German Republic,and residing at Luneburg, Germany, have invented certain new and usefulImprovements in a Method of ,Manufacturing Mold Powder, of which thefollowing is a specification.

In former times witch-meal (lycopodium) has been employed asmold-powder, but as its price is high various surrogates have beenintroduced by and by,as, for in stance, carbonate of lime,kicselgnhr,tripolipowdeiybrown-coal, and a lot of other substances. Asthe chief property of the moldpowder must be its complete repulsion towater, the substance used is soaked with a comparatively considerableamount of a suitable wax or oil, a suitable fatty acid, or the like,whereby it is rendered water-repulsive. The quantity of the respectiveadded substance (wax, etc.) amounts, as a rule, from 3 to 10%, but insome cases it is considerably greater.

Now, I have discovered that a large part of the wax or other addedwater-repulsive substance can be saved if pieces of unglazed muflles orthe like as used in connection with the burning of chinaware orclay-ware are ground, and this powder is used as a substitute for thecarbonate of lime, kieselguhr, etc., etc. Only about of the wax, etc.,is neededto render the composition completely water-repulsive and tolmpart it also the certain other properties necessary for a usefulmold-powder. EwampZe.-2O0 kg. of finel ground unglazed mufile-pieces orthe li e are mixed with 1 kg. of "wax or a suitable equivalent, and witha small amount of a dyeing substance of such a color that thecomposition a'ssumesa color like, or similar to, that produced bywitch-meal, the mixingbeing effected preferably by means of astirring-device and at a temperature of from 7 0 to C. The mixing bystirring is continued for about 1 hour, when a homogeneous compositionwill be obtainedthat can be employed Application fil ed November 21,1924. Serial Np. 751,413.

as mold-powder either at once or after having been sifted.

I claim:

1. The method of producing a mold-powder, consisting in grindingunglazed fire clay muffle-pieces and mixing the powder obtained with waxat a temperature.

which is only a little higher than the fusing ing temperature of thewax, substantially as set forth. I 1

4. The method of producing a parting powder consisting ingrindin piecesof unglazed burnt fire clay and mlxing the powder obtained wtih wax at atemperature which is a little higher than the fusion temperature .of thewax.

5. The method of producing a partingpowder consisting in grinding piecesof unglazed burnt fire clay and mixing the powder obtained with aboutone-half per cent of wax at a tem erature which is a little higher thanthe usion temperature of the wax.

6. As a new article of manufacture a parting powder consisting of amixture of finely groundburntunglazed fire clay with wax which has beenincorporated at a temperature slightly above the fusion temperature ofthe wax.

7 As a new article of manufacture a 1parting powder consisting of amixture of nely ground unglazed mufiie pieces with wax which has beenincorporated at a temperature slightly above the fusion temperature derso obtained with a water repellent maof the wax. I terial. n

8. The method of producing a parting 10. As a new article of"manufacture a powder consisting in grinding pieces of unparting powderconsisting of finely ground 5 glazed burnt fire clay and intlmatelymixing burnt unglazed fire clay with which has been 15 the powder soobtained with a water repelthoroughly incorporated a water repellentlent material. material.

9. The method of producing a parting In testimony whereof I have afiixedmy powder consisting in grinding unglazed signature. muflle pieces andmixing intirnately the pow- KONRAD MULLER.

